// 双指针
var twoSum = function (numbers, target) {
  let left = 0;
      right = numbers.length - 1;
  while (left < right) {
    let sum = numbers[left] + numbers[right];
    if (sum == target) return [left + 1, right + 1];
    if (sum < target) left++;
    if (sum > target) right--;
  }
}